Method of securing a bearing race by welding using heat

ABSTRACT

The invention concerns a method of securing a bearing track which is journalled on a hollow shaft against rotational movement relative to the shaft. The bearing inner track is journalled against a step on the shaft and abutted by a retaining collar mounted on the shaft. An electron beam is applied to the bore of the shaft in a radial direction to penetrate firstly the shaft wall and then the retaining collar to weld them together so that a residual axial compressive load is produced sufficient to hold the bearing track against rotation relative to the shaft.

FWHOQ 13W EbhWnhlh ilnrted States Patent [151 3,694,616 Brealey 1451Sept. 26, 1972 [54] Y METHOD OF SECURING A BEARING 2,308,307 1/1943Robinson ..29/471.1 X RACE BY WELDING USING HEAT 3,245,273 4/1966 Coperet al ..287/52.07 3,203 268 8/1965 Manoni et a1 ..287/5207 72 lnventor.Edward Re lnald Breale Derb 1 England g y 3,185,815 5/1965 Anderson..219/121 EB 1,810,028 6/1931 Paszkowski ..287/52.07 I 1 AsslgnwRolls-Royce Llmltedr Derby. 5 1,840,926 1/1932 Williams ..2s7/52.07gland 3,460,237 8/1969 McClintock ..29/474.3 [22] Filed: Nov. 3, 19703,512,612 5/1970 Bragg et al ..219/121 EB [21] Appl' 86581 PrimaryExaminer-.l. V. Truhe Assistant Examiner-Gale R. Peterson 4 [30] ForeignApplication Priority Data Attorney-Stevens, Davis, Miller & Mosher Nov.26, 1969 Great Br1ta1n ..57,807/69 ABSTRACT [52] US. Cl ..219/121 EB,287/5207 The invention concerns a method of securing a bear- [51] Int.Cl. ..B23k 15/00 i g tra k which is journalled on a hollow shaft againstField of Search 29/474-3, rotational movement relative to the shaft. Thebearing 29/4733, 498, 148-4 A, 14915 B; inner track is journalledagainst a step on the shaft and 308/256; 287/5207 abutted by aretainingcollar mounted on the shaft. An electron beam is applied to thebore of the shaft in a [56] References C'ted radial direction topenetrate firstly the shaft wall and UNITED STATES PATENTS then theretaining collar to weld them together so that a resldual axlalcompressive load 1s produced suffi- 3562888 2/1971 Settle "219/121 EM Xcient to hold the bearing track against rotation relative 3,250,5815/1966 l-lonroth ..29/148.4 A X to the h f 2,536,784 1/1951 Tamm..29/148.4 A X 3,458,683 7/ 1969 Canonico et a1. ..219/ 121 E 4 Claims,2 Drawing Figures PATENTED I 3,694,616

sum 1 OF 2 v INVENTOR EDWARD REGINALD BREALEY ATTORNEYS PATENTEDSEPZSI972 3 694 616 sum 2 OF 2 FIGZ A METHOD. OF SECURING A BEARING RACE BYWELDING USING HEAT bearing race journalled on a hollow shaft it is thecommon practice to secure the bearing race against movement relative tothe shaftby compressing it against a step or other form of stop on theshaft by means of a nut engaging with a threaded portion of the shaft, alock washer being interposed between the nut and the bearing race toprevent the nut'from rotating loose.

In this invention we propose another method of members togethercomprising'the step of directing a concentrated beam of heat energysubstantially radially of the shaft member to penetrate firstly theshaft member and then the. annular member to weld said members togetherso that a force is produced in the assembly after welding which urgesthe annular member towards the stop.

Inja preferred embodiment of the invention the annular member is aretaining collar mounted on the shaft to abut an inner track of a rollerbearing which is journalled on the shaft against a step on the shaft. Anelectron beam is applied to the bore of the shaft in a substantiallyvradial-direction to penetrate firstly the shaft wall and then theretaining collar to weld the shaft and retaining collar together so thata residual axial compressive load is produced sufficient to hold thebearing inner track against rotation relative to the shaft.

The method of securing an annular ring such as a bearing race againstmovement relative to the shaft as proposed by this invention has anadvantage over the aforementioned known method in that it can be used inassemblies where lack of space precludes using a nut on a threadedportion of the shaft.

One embodiment of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a roller bearing journalledon a hollow shaft.

FIG. 2 is a longitudinal sectional view of a roller bearing journalledin the bore of a hollow shaft.

In the FIG. 1 an inner race 1 ll of a roller bearing 12 is journalled ona hollow shaft 13 against a step 14 on the shaft. A retaining collar 19is mounted on the shaft and compressed firmly during assembly againstthe bearing inner race by an axial load, indicated by arrows 22, from anexternal source which is not shown, during welding of the collar l9 intoplace on the hollow shaft 13.

The fillet 15 of the step 14 is of a smaller radius than the adjacentrounded chamfer 16 on the bearing inner race in order that the end face17 of the bearing inner race can abut the flat face 18 of the step 14.

The retaining collar 19 is welded to the shaft by means of an electronbeam, indicated by the numeral 23 in the drawing, applied in asubstantially radial In an assembly comprising an annular ring such as aaccording to theinvention a method of welding said 7 produce-asubstantially radial annular weld 26 securing the retaining collar tothe shaft. The welding operation causes expansion on heating followed bycontraction on cooling in the welded parts normal to the line of theweld. The expansion and contraction are proportional to the amount ofheat dissipated and are therefore proportionalto the width of the weld,that is to say, to. the dimension of the weld in the direction parallelto axis 24. The mean width of the weld in the shaft wall is greater thanthe mean width of the weld in the retaining.

Thus, on cooling the contraction in the shaft .overlength a (between theweld 26 and face 18) will be greater than the contraction in collar 19and inner race 11 over the samelengtha because more heat will have beendissipated in the shaft. After the external load 22 is removed from thecollar the bearing inner track will be left permanently compressedbetween the step 14 and the retaining collar 19. This compression isbalanced by an axial tension in the shaft wall.

When it is necessary to replace the roller bearing the retaining collaris machined off. The groove 25 is then recut in the bore of the shaft.Anew roller bearing is journalled on the shaft and a new retainingcollar mounted and welded to the shaft as already described.

In FIG. 2 the bearing 31 is journalled in the bore of the shaft 32against an internal shoulder or step 33 and the retaining collar 34 ismounted in the bore and held abutting the outer race 35 of the bearing31 by an external load indicated by arrows 22. The bearing outer track35 is compressed between the step 33 and the retaining collar 34 toprevent movement of it relative to the shaft by an electron beam weldfrom a beam 23 applied round the outer periphery of the shaft 32 topenetrate the shaft wall and the retaining collar 34 in a substantiallyinward radial direction to weld them together and produce a residualcompression load in the bearing outer race 35.

We claim:

1. A method for securing a bearing race on a hollow shaft having a stopformed on the external surface thereof against rotational movement withrespect to said shaft, comprising the steps of:

mounting said bearing race externally on said shaft abutting said stop;

mounting a retaining collar externally on said shaft in abuttingengagement with said bearing race; applying an external force to saidcollar in the direction of said bearing race;

directing a concentrated beam of heat energy substantially radiallyoutwardly of the longitudinal axis of said shaft;

penetrating first said shaft and then said collar with said concentratedbeam to weld said shaft and collar together; and

maintaining said applied external force during said welding step tomaintain said bearing race in abutting engagement with said stop;

wherein, after completion of said welding step said shaft and collarcontract by different amounts to urge said collar and said bearing racetowards said stop.

2. An article made by the method of claim 1.

3. A method for securing a bearing race on a hollow shaft having a stopformed on the internal surface thereof against rotational movement withrespect to said shaft, comprising the steps of:

mounting said bearing race internally on said shaft abutting said stop;

mounting a retaining collar internally on said shaft in abuttingengagement with said bearing race; applying an internal force to saidcollar in the direction of said bearing race;

directing a concentrated beam of heat energy substantially radiallyinwardly of the longitudinal axis of said shaft;

penetrating first said shaft and then said collar with said concentratedbeam to weld said shaft and collar together; and

maintaining said applied internal force during said welding step tomaintain said bearing race in abutting engagement with said stop;

wherein, after completion of said welding step said shaft and collarcontract by different amounts to urge said collar and said bearing racetowards said stop.

4. An article made by the method of claim 3.

1. A method for securing a bearing race on a hollow shaft having a stopformed on the external surface thereof against rotational movement withrespect to said shaft, comprising the steps of: mounting said bearingrace externally on said shaft abutting said stop; mounting a retainingcollar externally on said shaft in abutting engagement with said bearingrace; applying an external force to said collar in the direction of saidbearing race; directing a concentrated beam of heat energy substantiallyradially outwardly of the longitudinal axis of said shaft; penetratingfirst said shaft and then said collar with said concentrated beam toweld said shaft and collar together; and maintaining said applIedexternal force during said welding step to maintain said bearing race inabutting engagement with said stop; wherein, after completion of saidwelding step said shaft and collar contract by different amounts to urgesaid collar and said bearing race towards said stop.
 2. An article madeby the method of claim
 1. 3. A method for securing a bearing race on ahollow shaft having a stop formed on the internal surface thereofagainst rotational movement with respect to said shaft, comprising thesteps of: mounting said bearing race internally on said shaft abuttingsaid stop; mounting a retaining collar internally on said shaft inabutting engagement with said bearing race; applying an internal forceto said collar in the direction of said bearing race; directing aconcentrated beam of heat energy substantially radially inwardly of thelongitudinal axis of said shaft; penetrating first said shaft and thensaid collar with said concentrated beam to weld said shaft and collartogether; and maintaining said applied internal force during saidwelding step to maintain said bearing race in abutting engagement withsaid stop; wherein, after completion of said welding step said shaft andcollar contract by different amounts to urge said collar and saidbearing race towards said stop.
 4. An article made by the method ofclaim 3.